Sheet-metal can and method of making the same



Jan. 6, 1931. J.,F. WERDER 1,788,261

SHEET METAL CAN AND METHOD OF MAKING THE SAME Z'SheetS-Sheet 1 Filed Oct. 29, 1927 Jan. 6, 1931. 1,788,261

SHEET METAL CAN AND METHOD OF MAKING THE SAME Filed 001;. 29; 1927 2 Sheets-Sheet 2 3. Q/m Mz Patented Jan. 6, l93.1

UNITED STATES PATENT OFFICE JOHN F. WERDER, oF-cLEvELAfin, 01 10, assrenon. or ONE-HALF 'ro EDMUND ROGERS Application filed October 29, 1927. Serial No. 229,629.

This invention relates'to containers or. receptacles, and more particularly to sheet metal containers commonly known as cans. The object of the invention is 'to provide a 6 can or container capable of withstanding a relatively high fluid pressure, and which, at the same time, shall be relatively cheap to manufacture, so as to make possible commercial production on a large scale.

Heretofore, so far as I am aware, receptacles or containers designed to hold a fluid under pressure have been successfully constructed only by the use of welded or riveted joints, or .by the employment of seamless drawn tubing. Such containers have therefore been more or less expensive to manufac ture, the cost of production prohibiting their use for packages which are intended to bediscarded after having been emptied of their contents.

I have found that by following my improved -method of construction, cans or containers can be made cheaply of sheet metal having seams formed by crimping in the usual way, and will be capable of withstanding relatively high internal pressure, such, for example, as fifty to seventy-five pounds to the square inch,

While my improved can or container is adapted fora large number of uses, itis especially designed asa package for liquids containing a dissolved gas, such as carbon dioxide, and held under pressure. Packages s of this kind are usually provided witlra man-Ms ually controlled discharge valve .by means of which the contents may be dispensed as desired, as shown in my co-pending-application, Serial No. 112,584, filed May 29, 1926. The present invention, however, relates only method of making the same.

In order that the invention may be readily understood, referenceis had to the accompanying drawings, forming part of this specification, and in which Figure 1 is a view partially in side elevation and partially in longitudinal section, showing a can as made and assembled at an ordinary can factory;

to a special form of-joint or seam and the Figure 6 is a transverse section on the line,

66 of Figure 5 Figure 7 is a fragmentary transverse section on an enlarged scale, showing the final appearance of the longitudinal seam after being soldered;

Figure 8 is a view partially in side elevation and partially in longitudinal section,

showin the step of soldering the head seam on the lnside; and

Figures 9 and 10 are views similar to Fig- I ure 7 the first showing a modified form of crimped seam and the second showing such a seam, after having been stretched and soldered, in accordance with my improved method.

Referring to the drawings in detail, and

more particularly first to Figures 1 and 2,

the initial step of my method consists in -forming a.cyl1ndrical can having a body 1 and heads 2 and 2'. Each of these heads is provided at its periphery with a flange 3 adapted to: fit over and embrace the end of the body in the usual manner. The heads are substantially fiat, that is, they have no portion projecting beyond the plane of their desirable inorder to faciliedge, this being tate the handling of the heads in the can makingv machine. The heads, however, preferably have an inner-depressed portion 4, joined to the outer portion by an annular corrugation 4 and the. upper head is pro- 1 vided at its; center with a perforation 5 formed b punchin through the metal from the outsi c with a s arp pointed punch, thus forming a-- curled inner. edge, as illustrated in Figures ,3 .and 4, and as shown and de scribed indetail in my above mentioned copending application.

which, in the final form of the can, constitute feet to cause the same to stand upright, all as described in my said co-pending application. i

The body 1 of the can, as shown in- Figures 1 and 2, is provided with the usual longitudinal crimped seam 7, such seam comprising a portion a which is bent over and engaged with'the outturned edge of the underlying portion, the metal adjacent the seam being bent rather sharply, as indicated at b in Figure 2. This is commonly known as an outside seam.

A can constructed as above described, even with the heads soldered on, is wholly incapable of successfully withstanding relatively high internal pressures such as I propose to employ, and in order to render such can capable of withstanding these pressures, I proceed as follows.

I first bend or crimp inwardly the flanges 3 of the heads, as shown'in Figure, 3, such flanges being pressed in until they form an acute angle with the plane'of the head and until the diameter of their extreme edge is less than their diameter in the plane of the head itself. The adjacent edges of the body 1, over which the flanges 3 fit, is also bent during this crimping operation so as to confornl substantially,with the inside of the flanges,'and thus produce akind ofinterlocking joint which tends to prevent the removal of the head. In order to efl'ectively secure the heads in position, however, I apply sults.

solder around the edges of the flanges 3, as

indicated at 8-in Figure 4. This forms a strong and permanent joint and produces compressed air, and this is introduced.

through the opening 5 by means of a pipe 7 having a collar 2, which is preferably secured to the head 2 by solder, as described in my above mentioned application. Prior to the blowing operation, however, the body of the can is preferably enclosed within a mold or die X. which is slightly larger in diameter than such body. thus permitting a certain amount of expansion, while at the same time serving to limit the expansion to the proper amount.

The can being enclosed in the die. as shown in Figure 5, compressed air is admitted through the tube y. This produces two re- In the first place, it causes the heads 2 and 2' t0 bulge out into convex shape, as shown in Figure 5, and also as illustrated and described inmy said co-pending application. In the seoond place, it subjects the crimped seam 7 to a transverse stretching means of a readily fusible which results in somewhat deforming this seam from its original condition. The relative appearance of the seam before and after this stretching operation is illustrated in Figures 2 and 6, the expanded form being also more clearly shown in Figure 7, it being understood. of course, that Figures 6 and 7 are somewhat exaggerated in order to make the action clear. It will be seen that the bend I) in the metal is somewhat straightened out, or at least the angle is rendered much more obtuse, and it will be noted that the folded over portion a has been caused to slightly separate from the underlying portion. In other words, the crimped seam has been partially disrupted, and if the action had not been limited by the die. complete rupture of this seam would have occurred. However, as will be obvious, the size of the die is so chosen that further expansion is stopped, after the seam has been stretched, and slightly deformed, as shown in Figures 6 and 7 It would be possible, perhaps, for the operator. by exercising great skill and care, to shut off the pressure and stop the expansion at the proper point. without the use of the die X. It has been found, however, that the use of such a die great-1y facilitates the work and renders the' results accurate and certain. I Referring again to Figs. 2, 6 and 7, it will be seen that, in its original condition, the angle 6 is relatively sharp. and circumferential stress exerts its disruptingaction on the seam through a comparatively long lever arm, namely the distance from the bend?) to the outside of the seam. lVhen, however, the can has been deformed as shown in Figs. 6 and 7. and the bend I) somewhat straightened out. the lever arm through which stress is exerted upon the seam is obviously reduced, and the seam will therefore hold better.

After the expanding operation. above described. the stretched and partially deformed longitudinal seam is permanently and tightly sealed by applying solder along the outside of the seam, adjacent the folded portion a, as clearly shown in Figure 7. It will be seen that after this solder is applied, no

further stretching or deformation of the .parts,'under internal pressure, is possible.

The next and final step in the manufacture of my improved can consists in removing the through the opening 5, a small lump of solder.

as shown at 10 in Figure 8 The can is heated airpipe y, and in dropping into the can in my said co-pending application, and the 1 can may then be filled with the desired liquid in any suitable manner.

Instead of making an outside seam, as shown in Figures 1 and 2, I may form the can with what is known as an inside seam, as

illustrated at 7 in Figure 9. In .this case, the

folded over portion a lies on the inside of the can and the metal is sharply bent, as indicated at I). Figure 10 shows the appearance of this form of scam after having been subj ected to the blowing or expanding operation. It will be seen that the folded over portion a has tended to slightly separate from the adjacent wall of the can, and that the bend b has tended to straighten'outa In this case, the solder is applied along the scam in the crack adjacent to the bend b. As described in connection with the outside seam, the straightening of the bend 72 reduces the lever arm through which the stress acts upon the seam, and, as in the former case also, reduces the tearing efl'ect produced on the solder, thereby making the joint stronger.

While either outside or inside seams may be employed, in carrying out my improved method, I prefer .to use the outside seam, as shown in Figures 2, 6 and 7, as this gives superior results.

Bycrimping on and soldering the heads, as

shown, and by expanding and soldering the longitudinal seam, I am enabled to produce. at a very low cost of manufacture, a sheet metal can or package capable of successfullv holding internal fluid pressure strong enough to effectively discharge the contents of the can through the dispensing valve referred to. and* toproject a stream of liquid form such valve to relatively great distances, and when my improved can is employed for containing lubricating oil, paints, fire extinguishing compounds and the like, it is thoughtthat the many advantages thereof will be apparent without further discussion.

What I claim is 1. A sheet metal can comprising body and heads, the ends of the body flaring outwardly, said heads having peripheral flanges lying wholly outside the body and bent over the outwardly flaring ends of the body into an inwardly inclined position forming an acute angle with the planes of the heads and soldered to the edge portions of the body.

2. A sheet metal can comprising body and heads, sa'id heads having peripheral flanges bent over the ends of the body into an inwardly inclined position forming an acute angle with the planes of the heads, one of said heads being soldered to the end of the body both inside and outside. the completed joint comprising only two. thicknesses of metal. I

3. The method of making a sheet metal can having seams capable of withstanding fluid pressure which comprises forming a can body with the usual crimped longitudinal seam, expanding the body so as to stretch and partially open said crimped seam, thus decreasing the leverage with which stresses act upon said seam, and then applying solder along said partially opened seam to securely seal the same.

4;. The method of making a sheetmetal can having seams capable of withstanding fluid pressure which comprises forming a can body with the usual crimped longitudinal seam, securing heads to such body, introducing pressure fluid into the can to expand the same and thus stretch said crimped seam transversely, and then applying solder along said v stretched seam to securely seal the same;

5.- The method of making a sheet metal can having seams capable of withstanding fluid pressure which comprises forming a can. body with the usual crimped longitudinal seam, applying flat heads to such body and soldering on said heads, introducing pressure fluid into the can to expand the same and thus cause both the heads to bulge out into convex shape and the longitudinal crimped seam to be stretched transversely, and then applying solder along said stretched seam to securely seal the same.

6. The method of making a sheet metal can having seams capable of withstanding fluid pressure which comprises forming a can body with the usual crimped longitudinal seam, applying flat heads .to such body and soldering on said heads, introducing pressure fluid into the can to expand the same and thus cause both the heads to bulge out into convex shape and the longitudinal crimped seam to lie-stretched transversely, and then applying solder along said stretched seam and around the inside of the seam joining one of said heads to the body.

7. The method of making a sheet meta] can having seams capable of withstanding fluid pressure which comprises forming a can body with the usual crimped longitudinal seam having the folded over portion on the outside of the can, expanding the body so as to stretch or deform said crimped seam, partially separating the parts thereof, and decreasing the leverage with which stresses act upon said seam, and then applying solder on the outside along the seam so as tor secure the partially separated parts together and produce a fluid tight joint.

8. The method of making a sheet-metal can having seams capable of withstanding flui pressure which comprises forming a can body with the usual crimped longitudinal seam having the metal sharply bent adjacent thereto, expanding the body soas to stretch said seam transversely and thus partially straightthe tearing action on the solder, whereby the parts are securely held against further yieldmg.

9. The method of producing 'sheet metal cans capable of resisting high internal pressures which comprises forming a cylindrical can body, soldering flat heads to the ends of said body, and thereafter subjecting the assembly to an internal fluid pressure sufficient to cause a bulging and permanentdeformation of said heads.

10. The method of producing sheet metal cans-capable of resisting high internal pressures which comprises forming a cylindrical can body, soldering flat heads to the ends of said body, and thereafter introducing into the can through a pipe fluid under pressure sufliciently strong to cause a bulging and permanent deformation of said heads.

- 11.- The method of producing cans capable of resisting high internal pressures which consists in forming a cylindrical can body, soldering to said body heads with central depressions whereby the assembly has recessed ends, and thereafter subjecting the assembly to an internal pressure suificient to cause a bulging and permanent deformation of the ends of the can.

12. The method of forming a can, capable of resisting high internal pressures which consists in forming a cylindrical can body, securing to said body flat sealing heads with annular corrugations or depressions, whereby the assembly has recessed ends and can be passed through the guides of the usual can making machines, and thereafter subjecting the assembly to an internal pressure suflicient to cause a bulging and permanent deforma tion of the ends of the can by the yielding of the corrugations.

13. The method of making sheet metal cans comprising applying to the end of a cylindrical body a head having a peripheral flange extending /at substantial right angles to the plane thereof and embracing said body pressing or crimping inwardly the edge of said flange and the adjacent portion of said body so as to cause said flange to extend in a direction forming an acute angle with the plane of the head, and then soldering-said flange to the body.

In testimony whereof I aflix my signature.

' JOHN WERDER. 

